Question about wiring

I have an efm boiler w/2 heat zones. When the second heat zone turns on only the pump runs till the boiler temp goes down and then the boiler kicks on. When the first heat zone turns on the boiler and the pump turns on at the same time. My question is can I wire and how do I wire only the pump to turn on when the first heat zone turns on? The boiler turn on and off by it self to keep temp in it,so I think I can do this but I'm not sure how.

Now the reason I want to do this. The wife likes to play with the thermostat, Last year I set it at 68 get the fire set and then come home from work some days and it's turned up to 72-74 and there a lot of unburnt coal from the boiler running till the house comes up to temp even though the boiler is up to temp it just keeps running till the thermostat shuts it off.

Any help would be great so I don't have to duck tape her to the chair before I leave for work.
Only kidding about the duck tape but I have thought about it.

I would suggest you google your aquastat and find the recommended wiring for it. Each model has a few suggested wiring options available. Check pages 7-11 here and you will see what is doable for that unit.

http://customer.honeywell.com/techlit/p ... 0-2278.pdf

I think we have all had our share of duct tape moments.

Download the EFM Install and Operation manual from the EFM website on the 520... Go to page 15. It sounds like your setup is like this... If it is my guess is you have an L8124A and if you do the circulator and stoker motor both start when the contacts close at the thermostat. The reason your other zone does not is because it may not be tied back to the ZC and ZR terminals. You could run another R845A relay and use that to run your circulator and only use the L8124A to maintain your furnace. So , both circulators would be running off of R845A relays with the thermostats tied to them and not any tied to the L8124A. Can anyone else here confirm my idea?

I believe that is correct, but wanted to check first. The 8124A controls the one aquastat and the 845A the other, but I'm not suRre if the 845 will start the burner through ZR, maybe?

I finally had time to install the relay. It works great, now only the pump kicks on with the t-stat and not the boiler. Thanks guys. You have saved me a lot of wasted coal and money.

Thank you

TzHauling...glad to hear you got what you wanted with your wiring. Can you confirm for me what it is you ended up doing to get the circulators ONLY to come on during call from the thermostat? As mentioned in one of the above posts my wiring set up is now exactly like page 15 of the EFM manual. I have the problem that when my zones call for heat and the stoker runs it always get too hot and hits the high limit during the spring and fall. I've been averaging about 4-6 outfires a week lately no matter how I play with my settings. After some GREAT help from this forum I will get a working formula for about 3-4 days and then the weather will shift and it's back to hell for me again. If I could change my wiring this way maybe I could regulate the temperature better in spring and fall. Hell if it really works I'll wire it up with some switches that I could do a "summer/winter" mode and have it run normally when it's cold enough to handle it. Thanks!! ~Jeremy

I had one outfire in the efm stoker during the first week. It was because the second high limit was exceeded and it requires a manual reset. I moved that up to 240 and set the boiler aquastat at 150/190 with the feed rate at 5 and air at 8 (Blaschak coal). Last week when the temps were in the 60/70s, the boiler sat most of the day at 220, with only an occasional call for heat from the office, and the timer rarely worked, but the fire never went out. Each morning I was surprised that it was still lit.

Stoker....wow I thought I had a "large" spread with my feed at 4 and my air at 5. Although I don't know if I'm getting enough complete burn on my coal yet so maybe I'll push it up more...I was just reluctant because I thought they had to stay closer. That's exactly how my unit has been running. Always flirting with the high limit cut out and some cycles the timer doesn't run. I think it's enough cycles not running combined with a infrequent demand for heat that keeps pushing mine out. I'm gonna try and figure out this wiring and change it up today and see how this week goes.

I'm not to good at explaining things, so I will take some pictures and give it a try tomorrow after I get home from work.

TZ thanks...I think I got a working system though. I switched over my thermostat wires and my ciculator wires to the R845A and just threw a switch in the ZR line. I labeled that switch Winter (ON, so the stoker will run on call for hear) and Summer (OFF, the stoker will not fire unless the aquastat needs water temp). So far this has worked beautifully. My temps are now down far away from my high limit so my timer runs freely. This morning when the thermostats called for heat the house seemed to warm up just fine and I just had a nice hot shower. I will see what it looks like when I get home from work today yet. Thank you very much for your information and your time. If this works I will be doing some rewiring this weekend!

stoker-man wrote:set the boiler aquastat at 150/190

Just curious, why the big spread? 40* is a bunch.

It's 40 degrees in Winter and up to 50 degrees in Summer. The reason being that after stoking, there is a large mass of red hot coal in the pot and that creates enough heat to raise the boiler another 30 degrees easily, after the stoker has shut down. With low demand for domestic or heating water, there is nothing to draw down the boiler water temperature and it can sit there for hours and not lose much heat.

Add to that, if your high limit is 190 and the temperature drops to 185 and the timer kicks in its half hour cycle (below the high limit), you could easily jump to well over 200 degrees. So, it's an experimental experience to get all the aquastats set properly so the fire doesn't go out.

In the efm boiler, with the nightly setback of 10 degrees, the cold water returning to the boiler in the morning can draw down the boiler temperature to 120 and affect the outfire control which will shut down the stoker until it's manually reset. On the other end, the second high limit aquastat, which must also be manually reset, can be affected if the operating aquastat high limit is set too high. The second aquastat is 240 degrees maximum. Both of these shutdowns have ocurred. And finally, the operating aquastat must have a 40 degree range, so you see all the stuff that must be worked out with the extra aquastats.

Jeremy, I'm a little curious as to your wiring. I'm glad everything is working out well, but in the summer position, with no call for heat through the 845A (because the circulator doesn't work in the Summer, how is this switch doing anything?

Seems to me, you solved your problem through some other means than by adding the Summer/Winter switch, since the aquastat and relay will do the same things without the switch.

(ON, so the stoker will run on call for hear) and Summer (OFF, the stoker will not fire unless the aquastat needs water temp).

Stoker,

Maybe the "summer" mode is a bit of a misnomer. Actually the "summer" mode is what I seem to need to run in the spring and fall (still have it in summer mode right now). In the actual summer the unit worked great b/c it only ran on the timer and I had to aquastat spread enough that the temps stayed perfect all summer long. The problem I run into into the spring/fall is when the zones call for heat in the morning (greatly increasing my boiler temp) but then will not call for heat the remainder of the day. I think it's that mass of heat that comes from stoking plus the continued running of the timer that gets me to the high limit and outfire. I'm not 100% of the reason but no matter what do to the radiation of the baseboards, the size of the room the stoker itself is in, the feed/air combo I need for the quality of coal...I always have "too much heat" in the spring/fall. Especially this fall with some of these unseasonably warm temps.

What I think this switch is doing for me (and I could very well be wrong, and just frustrated and willing to try anything) is allowing the stoker to operate like it does during the summer but still circulate for heat. I'm hoping this winter when it is truly cold I can switch it back and maximize efficiency. If I was set at 140/200, 150/200, or 160/200 I would always be at temps in the 200 range. If conditions were perfect and I was lucky it would last a day or two but then eventually it would hit 200 and shut down long enough to go out. Now at 160/200 I stay parked right at about the 180 range. Maybe I'm just fooling myself into thinking this a solution....

Sounds like you have too much coal feed. Cut back one tooth and make sure the air is low enough that it doesn't cause the fire to burn downward in the pot and then into the feed pipe.